The present invention relates medical imaging equipment, and more particularly transmitting image data over a network to any one of a plurality of output devices, such as printers and display workstations.
Large medical centers have several different types of medical imaging equipment including X-ray apparatus, computed tomography scanners and an magnetic resonance imaging system. All of these types of imaging equipment are capable of displaying the image of a patient on a video monitor OR FILM for viewing by medical personnel. Specific equipment within each of these types of imaging apparatus also are capable of short term storage of the digitized image data for later retrieval and display on the video monitors. However, the images ultimately are printed on photographic film for interpretation and retention. As a consequence, each piece of imaging equipment has a dedicated workstation with a high resolution video monitor and is attached to a particular laser printer which produces a hard copy of the medical image on photographic film. A particular imaging system is configured for its dedicated workstation monitor and attached printer to produce images of consistent high quality.
There is a trend in large medical facilities to connect the various types of imaging apparatus to a communication network which enables the images to be produced on film printers and workstations throughout the facility. This integrated network relieves medical personnel of having to go to the dedicated workstation or printer in order to obtain an image from the associated imaging device, instead the image can be sent to an image reproduction device near the medical personnel. In addition the same workstation or printer can be used to produce images that have been acquired by different pieces of medical imaging equipment. The network also may allow the medical personnel to retrieve images acquired in the past and archived in a memory device attached to the network. Thus the personnel can utilize a single workstation to compare a current image of the patient with one taken sometime ago, or to view images from many imaging systems at one conventient location.
With such a network and the increase of digital medical imaging workstations, a video display which produces a soft copy of the medical image is becoming the preferred mode of presenting medical images. This has caused an increased concern among the medical community, because each video monitor has its own luminance response characteristic for the conversion of digital picture elements into light for the display of information across the full dynamic display range. However, a particular monitor on the network no longer is dedicated to only one imaging system and thus is not calibrated for the images produced by that one system. This calls for a quality control procedure to ensure optimal display of medically significant information.
An additional need for quality control arises from the fact that images ultimately are interpreted by the radiologist as hard copy produced on photographic film. This requires that the hard copy images convey the same diagnostic information as the soft copy images and vice versa. Thus the hard copy images produced on a laser printer should be equivalent regardless of which printer was used to generate the film image. However, each laser printer also has its own intensity response characteristic. To complicate matters further, the print quality from any given laser printer is affected by changes in film type, chemistry of the film development process, and cleaning of the apparatus.
Therefore, it is desirable to ensure consistency and high quality among medical images regardless of the source or reproduction device and whether the output is a soft or hard copy. In other words, all of the images produced anywhere on the network should convey the same diagnostic information.